Here is the full list of all 49 Metro: Last Light Redux achievements. It takes around 30-35 hours to unlock all of the achievements on Windows.
Complete the HEAVY SQUAD level.
Complete the SNIPER TEAM level.
Complete the TOWER level.
Complete the KSHATRIYA level.
Complete the PAVEL level.
Complete all 43 of Artyom's hidden Diary pages.
Kill Pavel.
Complete the BRIDGE level without a kill.
Find and return the crying child's Teddy Bear.
Drink at every occasion.
Kill the Watchmen attacking the Railcar without taking any damage.
Complete the REVOLUTION level without killing and raising an alarm.
Watch the entire Theater Show.
Complete the FACILITY level without killing or raising alarm.
Disarm 10 Traps.
Kill 10 enemies in a row with Throwing Knives.
Complete the KHAN level.
Complete the ANNA level.
Complete the SPIDER LAIR level.
Complete the SEPARATION level without killing or raising alarm.
Open 10 locked safe boxes.
Spend 1 hour on the DEVELOPER level.
Save D6.
Complete the game in Survival Mode.
Destroy D6.
Complete the game in Spartan Mode.
Make Moskvin tell the truth with help from the Dark One.
Save the Bear from the Watchmen after the fight.
See all Visions in the Dead City.
Find out about the Reds' plans.
Remove your mask when Lesnitsky demands it.
Turn off 40 Lights without breaking them.
Kill the Rhino.
Kill 100 Mutants.
Spend 30 minutes' worth of Filters.
Rescue the Women and Children on the BANDITS level without raising alarm.
Stealthily kill 15 Enemies.
Burn 50 Cobwebs.
Make 10 Spiders flip belly-up.
Kill all armed enemies on the REVOLUTION level, including all reinforcements.
Kill 100 Human Enemies.
Escape from the Red Line.
Escape the chasing Nazis on the REICH level without being caught once.
Use 10 Lever Switches.
Complete the ECHOES level undetected by the Watchmen.
Free the Prisoners.
Finish the ASHES level without taking a hit.
Choose three primary weapons that use different ammo.
Complete training sequence.